When the system disclosed in the above-mentioned patent application was installed for use in connection with a mold conveyor which moved at a slow speed of about 1 inch per second and characterized by a jerky movement of the molds, the sensor means disclosed in said application resulted in erratic action. Thus, a precise alignment between the mold sprue cup and the ladle was not consistently maintained. The present invention is directed to a rotary pour system as disclosed in said application but with a modified sensor means particularly adapted for use with a slow and/or erratically moving mold conveyor.